Publications

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2015
Bedon, Chiara, Filipe Santos, Claudio Amadio, and Corneliu Cismasiu. "Passive and active control systems for adaptive glazing systems and envelopes." European COST Action TU1403 "Adaptive facades network" Industry Workshop. Delft, The Netherlands 2015.
Amarante dos Santos, Filipe, Corneliu Cismasiu, and Chiara Bedon. "Smart glazed cable façade subjected to a blast loading." Proceedings of the Institution of Civil Engineers-Structures and Buildings (2015): 1-10. Abstract

This paper investigates the dynamic behaviour of cable-supported glazing façades
subjected to medium-level air blast loads. Preliminary numerical studies are carried-out in
SAP2000 by means of a geometrically refined and simplified lumped-mass finite-element
numerical model, in order to assess the major effects of the design blast load in the main
façade components. As shown, both the glass panels and the cable system are able to
properly accommodate the incoming impulsive loads, typically involving extreme ...

2014
Cismasiu, Corneliu, Filipe Amarante P. dos Santos, and Ana I. M. Rodrigues. "Experimental and FE updating techniques for the unseating vulnerability assessment of a footbridge structure." The 4th International Conference on Dynamics, Vibration and Control. Shanghai, China: Shanghai Institute of Applied Mathematics and Mechanics, 2014. icdvc_2014.pdf
Cismaşiu, C., A. Narciso, and F. Amarante dos Santos. "Experimental Dynamic Characterization and Finite Element Updating of a Footbridge Structure." Journal of Performance of Constructed Facilities.10.1061/(ASCE)CF.1943-5509.0000615 (2014).Website
dos Santos, Filipe Amarante P., Corneliu Cismasiu, Pedro F. Gonçalves, and Mauricio Gamboa-Marrufo. "Smart glass facade subjected to wind loadings." Structures and Buildings. 167.12 (2014): 1-10.
Bernardo, Vasco, André Oliveira, Filipe Amarante dos Santos, and Corneliu Cismasiu Vulnerabilidade e reforço sísmico de uma passagem superior pedonal pré-fabricada. 5as Jornadas Portuguesas de Engenharia de Estruturas. Lisboa, 2014.artigo_jpee2014.pdf
2013
Cismasiu, Corneliu, and Filipe Pimentel Amarante dos Santos. "Shape Memory Alloys in Structural Vibration Control. Research at UNIC/DEC/FCT/UNL." International Conference "Tradition and Innovation". 60 Years of Civil Engineering Higher Education in Transilvania. Cluj-Napoca, Romania: UTCN, 2013. c60.pdf
dos Santos, Amarante F. P., and C. Cismasiu. "Bridge Hinge-Restrainers Built up of NITI Superelastic Shape-Memory Alloys." New Trends in Smart Technologies . Eds. Christian Boller, and Hartmut Janocha. Saarbrücken: Fraunhofer Verlag, 2013. 195-203.
and Amarante dos Santos, F. P. and Cismaşiu, Pamies Teixeira C. J. "Semi-active vibration control device based on superelastic NiTi wires." Structural Control and Health Monitoring. 20 (2013): 890-902.Website
2012
Cismasiu, C., and Amarante F. P. dos Santos. "Towards a semi-active vibration control solution based on superelastic shape memory alloys." 15th WCEE. Lisbon, Portugal 2012. 2012_wcee_0379.pdf
2011
dos Santos, Amarante F. P., and C. Cismasiu. "Bridge hinge-restrainers built up of NiTi superelastic shape-memory alloys." Smart Structures and Materials (SMART'11). 5th ECCOMAS Thematic Conference on Smart Structures and Materials SMART'11. Saarbrücken, Germany 2011. Abstractsantos_2011.pdf

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de Freitas, J., I. Moldovan, and C. Cismaşiu. "Hybrid-Trefftz displacement element for poroelastic media." Computational Mechanics (2011): 1-15. AbstractWebsite

The elastodynamic response of saturated poroelastic media is modelled approximating independently the solid and seepage displacements in the domain and the force and pressure components on the boundary of the element. The domain and boundary approximation bases are used to enforce on average the dynamic equilibrium and the displacement continuity conditions, respectively. The resulting solving system is Hermitian, except for the damping term, and its coefficients are defined by boundary integral expressions as a Trefftz basis is used to set up the domain approximation. This basis is taken from the solution set of the governing differential equation and models the free-field elastodynamic response of the medium. This option justifies the relatively high levels of performance that are illustrated with the time domain analysis of unbounded domains.

2010
by Cismasiu, Edited Corneliu Shape Memory Alloys. Scyio, 2010.Website
Cismasiu, Corneliu, and Filipe Amarante Dos P. Santos. "Shape Memory Alloys." Ed. Book Corneliu edited by: Cismasiu. ISBN: 978-953-307-106-0. Croatia: Scyio, Publishing, 2010. 127-154. Abstract
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dos Santos, Amarante F. P., and C. Cismasiu. "Comparison Between Two SMA Constitutive Models for Seismic Applications." Journal of Vibration and Control. 16 (2010): 897-914. AbstractWebsite

This paper analyses and compares the dynamic behavior of superelastic shape memory alloy (SMA) systems based on two different constitutive models. The first model, although being able to describe the response of the material to complex uniaxial loading histories, is temperature and rate independent. Thesecond model couples the mechanical and kinetic laws of the material with a balance equation considering the thermal effects. After numerical validation and calibration, the behavior of these two models is tested in single degree of freedom dynamic systems, with SMAs acting as restoring elements. Different dynamic loads are considered, including artificially generated seismic actions, in a numerical model of a railway viaduct. Finally, it is shown that, in spite of its simplicity, the temperature- and rate-independent modelproduces a set of very satisfying results. This, together with its robustness and straightforward computational implementation, yields a very appealing numerical tool to simulate superelastic passive control applications.

2008
dos Santos, Amarante F. P., and C. Cismasiu. "Comparison Between Two {SMA} Constitutive Models for Seismic Applications." Twelfth Conference on Nonlinear Vibrations, Dynamics, and Multibody Systems. Blacksburg, VA 24061 2008. Abstract
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Cismasiu, Corneliu, and Filipe Amarante P. dos Santos. "Numerical simulation of superelastic shape memory alloys subjected to dynamic loads." Smart Materials and Structures. 17 (2008): 025036 (12pp). AbstractWebsite

Superelasticity, a unique property of shape memory alloys (SMAs), allows the material to recover after withstanding large deformations. This recovery takes place without any residual strains, while dissipating a considerable amount of energy. This property makes SMAs particularly suitable for applications in vibration control devices. Numerical models, calibrated with experimental laboratory tests from the literature, are used to investigate the dynamic response of three vibration control devices, built up of austenitic superelastic wires. The energy dissipation and re-centering capabilities, important features of these devices, are clearly illustrated by the numerical tests. Their sensitivity to ambient temperature and strain rate is also addressed. Finally, one of these devices is tested as a seismic passive vibration control system in a simplified numerical model of a railway viaduct, subjected to different ground accelerations.

2007
Santos, F. P., and C. Cismasiu. "Shape memory alloys in structural vibration control." EVACES'07 - Experimental Vibration Analysis for Civil Engineering Structures. FEUP, Porto, Portugal 2007. Abstract

The unique superelastic behaviour exhibited by shape memory alloys (SMAs) allows the material to recover after withstanding large deformations. This recovery takes place without any residual strains, while dissipating a considerable amount of energy. This property makes the SMAs particularly suitable for applications in vibration control devices. Numerical models, calibrated with experimental laboratory tests, are used to investigate the dynamic response of vibration control devices. These devices are built up of austenitic superelastic wires. The energy dissipation and re-centring capabilities, important features of these devices, are clearly illustrated by the numerical tests. One of these devices is tested as a seismic passive vibration control system in a simplified numerical model of a railway viaduct.

2005
Silva, M. A. G., C. Cismaşiu, and C. G. Chiorean. "Numerical simulation of ballistic impact on composite laminates." International Journal of Impact Engineering. 31 (2005): 289-306. Abstract

The paper reports experimental and numerical simulation of ballistic impact problems on thin composite laminated plates reinforced with Kevlar 29. Ballistic impact was imparted with simulated fragments designed in accordance with STANAG-2920 on plates of different thickness. Numerical modelling was developed and used to obtain an estimate for the limit perforation velocity V50 and simulate failure modes and damage. Computations were carried out using a commercial code based on nite differences and values obtained are compared with the experimental data to evaluate the performance of the simulation. Good correlation between computational simulation and experimental results was achieved, both in terms of deformation and damage of the laminates. Future work is advanced to include the interposition of an outer ceramic layer as well as examining the influence of dry-wet and temperature cycles on the mechanical strength of the plates and their temporal evolution under accelerated ageing.

2004
2003
Silva, M. A. G., C. Cismaşiu, and C. G. Chiorean. "Low velocity impact on laminates reinforced with {P}olyethylene and {A}ramidic fibres." Computational Methods in Engineering and Science. Proceedings of the 9th International Conference EPMESC IX. Eds. V. P. Iu, L. N. Lamas, Y. - P. Li, and K. M. Mok. Macao, China: A.A.Balkema Publishers, 2003. 843-849. Abstract

The present study reports low velocity impact tests on composite laminate plates reinforced either with Kevlar 29 or Dyneema. The tests are produced using a Rosand Precision Impact tester. The experimental results obtained for Kevlar 29 are simulated numerically. The deflection history and the peak of the impact force are compared with experimental data and used to calibrate the numerical model.

Silva, M. A. G., C. Cismaşiu, and C. G. Chiorean. "Ballistic Simulation of Impact on Composite Laminates." Proceedings of the International Conference Constructions 2003. Vol. 2. Cluj-Napoca, Romania: The Technical University of Cluj-Napoca, 2003. 139-146. Abstract

The paper reports on numerical simulation of impact problems on fiber reinforced plastic composite laminated plates reinforced with Kevlar 29. The ballistic impact caused by STANAG-2920 projectile is analyzed to obtain an estimate for the V50 and the global damage. All estimate have been carried out using the finite difference numerical code AUTODYN-3D, are compared with the experimental data to illustrate the performance of the simulation. Good correlation between resulting simulations and experimental results is demonstrated both in terms of deformation and damage of the laminates and ballistic performance.

Freitas, J. A. T., and C. Cismaşiu. "Adaptive p-refinement of hybrid-{T}refftz finite element solutions." Finite Elements in Analysis and Design. 39 (2003): 1095-1121. Abstract

An adaptive p-refinement procedure for the implementation of the displacement model of the hybrid-{T}refftz finite element formulation is presented. The procedure is designed to select and implement automatically the degrees of freedom in the domain (displacements) and on the boundary (surface forces) of the element to attain a prescribed level of accuracy. This accuracy is measured on the strain energy of the system for a prescribed finite element mesh. Local measures of error can be easily accounted for. The performance of the adaptive procedure suggested is illustrated using two-dimensional potential problems.

Freitas, J. A. T., and C. Cismaşiu. "Hybrid-{T}refftz displacement element for spectral analysis of bounded and unbounded media." International Journal of Solids and Structures. 40 (2003): 671-699. Abstract

The hybrid-{T}refftz displacement element is applied to the elastodynamic analysis of bounded and unbounded media in the frequency domain. The displacements are approximated in the domain of the element using local solutions of the wave equation, the Neumann conditions are enforced directly and the surface forces are approximated on the Dirichlet and inter-element boundaries of the finite element mesh. Two alternative elements are developed to model unbounded media, namely a finite element with absorbing boundaries and an unbounded element that satisfies explicitly the Sommerfeld condition. The finite element equations are derived from the fundamental relations of elastodynamics written in the frequency domain. The numerical implementation of these equations is discussed and numerical tests are presented to assess the performance of the formulation.